Precipitation twinning

被引：42

作者：

Appel, F.

Fischer, F. D.

Clemens, H.

机构：

[1] GKSS Forschungszentrum Geesthacht GmbH, Inst Mat Res, D-21502 Geesthacht, Germany

[2] Montanuni Leoban, Dept Phys Met & Mat Testing, A-8700 Leoben, Austria

来源：

ACTA MATERIALIA | 2007年 / 55卷 / 14期

关键词：

twinning; titanium aluminides; high-resolution electron microscopy; micromechanical modelling; precipitation;

D O I：

10.1016/j.actamat.2007.05.007

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

The paper describes the heterogeneous nucleation of mechanical twins in a TiAl alloy containing Ti3AlC perovskite precipitates. Examination of the deformation structure by high-resolution electron microscopy has revealed that overlapping planar faults were generated at the perovskite particles. These faults can apparently easily rearrange into embryonic twins and subsequently grow into large twins. The nucleation mechanism was found to be closely associated with the misfit character and stress state of the precipitates. The structural data serves as input for the modelling of the precipitation-induced twinning process. Based on these calculations, the thickness and length of the embryonic twins can be predicted, which agree well with the experimental observations. (c) 2007 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

引用

页码：4915 / 4923

页数：9

共 37 条

[1]

APPEL F, 1995, MATER RES SOC SYMP P, V364, P493

[2] Microstructure and deformation of two-phase γ-titanium aluminides [J].